JPH04177701A - Composition for thick film resistor - Google Patents

Abstract

PURPOSE:To produce the title composition for thick film resistor in small fluctuation coefficient of resistance value in high resistance region and small variation coefficient in permanent resistance during short time overload at high voltage by a method wherein specific amount of stannate is added to a composition comprising glass powder containing ruthenate and lead. CONSTITUTION:The title composition for thick film resistor is composed of ruthenate represented by a chemical formula of Pb2 Ru2Ox wherein x is within the range of 6-7 and particle diameter not exceeding 1000Angstrom as well as lead silicate glass powder in the mean particle diameter not exceeding 10mum containing silicon oxide exceeding 10wt% and lead oxide also exceeding 10wt% or ruthenate powder represented by the chemical formula of Pb2Ru2Ox wherein x is within the range of 6-7 and particle diameter not exceeding 1000Angstrom as well as lead silicate glass powder in the mean particle diameter not exceeding 10mum containing silicon oxide exceeding 10wt% and lead oxide also exceeding 10wt%, stannate powder and organic vehicle while the content ratio of stannate in inorganic constituent in this composition is to be 0.2-2wt%. In such a constitution, the title composition for thick film resistor in small fluctuation coefficient of resistance value and small variation coefficient in permanent resistance during short time overload testing step can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a composition for a thick film resistor containing lead ruthenate used for forming electronic circuits.

[Conventional technology]

In recent years, thick film resistors using ruthenium oxide-based conductors such as ruthenium oxide and lead ruthenate have been widely used in circuit formation of microelectronic components. It has been widely used as an electrical conductor.

If lead ruthenate is used, the resistance value can be increased by 10 to 1
It can be set to any value of 0°Ω/mouth, the resistance value of the created resistor is not greatly influenced by the concentration of lead ruthenate in the conductive composition, and the rate of variation in resistance value (CV value) is small. It is from.

By the way, when creating a resistor using a ruthenium oxide-based conductive material such as lead ruthenate, for example, if the powder of the ruthenium oxide-based conductive material has a softening point of 450
A lead borosilicate glass powder with a coefficient of thermal expansion of about 6,500 and close to that of alumina is mixed with an organic vehicle, and then kneaded using a three-roll mill or the like to form a paste to obtain a composition for a thick film resistor. is screen printed onto an insulating substrate such as alumina to form a circuit pattern, dried, and fired. Then, in order to obtain a desired resistance value, the ratio of the conductive material and the glass is adjusted.

In recent years, for thick film resistors formed in this way, -
It is desired to improve the voltage resistance characteristics of the layer.

Specifically, the aV value in the high resistance range where the sheet resistance value is about IMΩ/mouth is 10% or less, and the permanent resistance change rate (hereinafter referred to as permanent resistance change rate) in the high voltage short-time overload test is 0. 2%
The following are required.

However, the conventional resistor compositions described above cannot satisfy this requirement. This is because, for example, even if a thick film resistor made using this composition has a sheet resistance of about 12 Ω/mm, which is generally considered to have a small permanent resistance change rate, the permanent resistance change rate will be This is because if the sheet resistance value is as large as about 15%, and if the sheet resistance value is greater than 100Ω/':, there is a drawback that the dependence of the resistance value on the conductive material concentration becomes thick.

Various compositions and methods have been proposed to overcome this drawback, but one of the most effective is the composition disclosed in Japanese Patent Publication No. 55-39883. This is a composition for thick film resistors that is made by adding BaTi0 and TiO to a composition consisting of a conductive pyrochlore-related oxide and glass. However, the permanent resistance change rate of a resistor with a sheet resistance value of about IMΩ/mouth made using this thick film resistor composition is 0.3 to 1%, which does not satisfy the above requirements. .

[Problem to be solved by the invention]

An object of the present invention is to provide a composition for a thick film resistor, which has a small rate of change in resistance value in a high resistance region and a small rate of change in permanent resistance due to short-term overload of high voltage.

[Means to solve the problem]

The present inventors have discovered that by adding a specific amount of lead stannate to a composition consisting of lead ruthenate and glass powder containing lead, a product that can meet the above requirements can be obtained, and the present invention has been achieved. . That is, the composition for a thick film resistor of the present invention contains lead ruthenate represented by the formula PbRuO, 22X in the range of 6 to 7, and a particle size of 1 ooo R or less, and 10% by weight or more of silicon oxide. lead silicate glass powder with an average particle size of 10 μm or less, containing 10% by weight or more of lead oxide, or ruthenium represented by the formula PbRuO with 22X in the range of 6 to 7 and a particle size of 1000 A or less The composition consists of an acid lead powder, a lead silicate glass powder with an average particle size of 10 μm or less containing 10% by weight or more of silicon oxide and 10% by weight or more of lead oxide, a lead stannate powder, and an organic vehicle. It is characterized in that the content of lead stannate in the inorganic components of the product is 0.2 to 2% by weight.

In constructing the composition of the present invention, lead ruthenate powder is prepared by mixing ruthenium oxide and lead oxide in a predetermined ratio, melting the mixture, cooling it, and pulverizing the mixture to a particle size of 1000% or less, and a lead ruthenate powder having an average particle size of 1,000% or less. It is made by kneading lead silicate glass powder with a diameter of 10 μm or less, lead stannate powder with an average particle size of less than 5 μm, and an organic vehicle, or by mixing ruthenium oxide, lead oxide, silica, alumina, etc. 100, which was melted, cooled, and ground to an average particle size of 10 μm or less.
It may be made by kneading a glass powder containing fine crystals of lead ruthenate of 0.02 or less, a lead stannate powder having an average particle size of less than about 5 μm, and an organic vehicle.

Lead stannate (PbSr+O) powder is, for example, pbo and SnO
Preferably, a predetermined amount of each is weighed and mixed in a ball mill using ethanol as a dispersion medium, then calcined at about 1000 C, and ground again in a ball mill to adjust the average particle diameter to less than about 5 μm. This is because, for example, the thickness of a normally formed resistor is about 15 μm at most, so if too large particles are present, the Cv value and withstand voltage characteristics will naturally deteriorate.

As the organic vehicle used in the present invention, those commonly used as bases for resistors can be used, and the composition thereof is not particularly limited. Further, the amount used is preferably 20 to 40% by weight of the entire composition so that a suitable resistor pattern can be formed by screen printing as in the past.

[Effect]

The lead ruthenate used in the present invention is a pyrochlore type conductive oxide, and its structure is made of a combination of two octants consisting of a cubic CaF structure, and the oxygen atoms are Ca? Enter the tetrahedrally coordinated position inside the cube of the structure. Of the oxygen in lead ruthenate, the oxygen at the diagonal position of the Pb atom tends to be missing, and as a result, the stoichiometric amount of oxygen varies from 6 to 7, and when expressed by the formula Pb Ru O, 2 2X The range of X is 6 to 7.

The most preferable lead ruthenate to be used is particle size 1.
000% or less, preferably 100-500R PbR
It is uO. This is because when the particle size exceeds 100OR, the CV value of a resistor made using the resulting composition becomes significantly large.

In addition, the lead silicate glass powder used is one containing 10% by weight or more, preferably 15 to 35% by weight of silicon oxide, and 10% by weight or more, preferably 50 to 80% by weight of lead oxide. In addition to these components, AIO, BO, MgO, Oak, Ba
d, TiO, ZrO, etc. may be included. If the particle size of the lead silicate glass used is too large, it will not be possible to mix the lead ruthenate powder and the glass powder uniformly, and the characteristics of the resistor made using the resulting composition will deteriorate. , the object of the present invention cannot be achieved. Therefore, the average particle size of lead silicate glass is 10μ
It is necessary that the thickness be 8 μm or less, preferably 8 μm or less.

In the present invention, lead stannate (PbSnO) powder is thought to play the role of separating the conductive network of lead ruthenate and increasing the resistance value, but in order to fully demonstrate this function, the amount of Pb5nO added is 0.2 to 2 of inorganic components
It is necessary to adjust the weight percentage.

When the amount of Pb5nO added is less than 0.2% by weight, there is almost no increase in the resistance value and no improvement in electrical characteristics, and when the amount added is more than 2% by weight, the resistance value increases but the variation in resistance value (
CV value) and withstand voltage characteristics deteriorate.

Preferably 0.5 to 1.5% by weight is desirable.

〔Example〕

Example 2 Ru2Ox6.7g, Pb068.1g, Si
○23.8g, AI O2,7g.

1,2 g of MgO was mixed and heated at 1000C for 3 hours to dissolve. This was put into water, rapidly cooled, and ground in a ball mill to obtain a powder with an average particle size of 7.3 μm.

The obtained powder is 200-800X fine Pb Ru○
It was a glass powder containing crystals. Next, lead stannate was ground in a ball mill using zirconia balls, classified to obtain Pb5nO powder with an average particle size of 3.2 μm, and this and the above glass powder containing PbRuO crystals were mixed in a predetermined ratio. 30 parts by weight of a terpineol solution of ethyl cellulose was added to 70 parts by weight of this mixture and kneaded in a three-roll mill to obtain a composition for a thick film resistor.

This composition was printed on an alumina substrate provided with Ag/Pd electrodes using a pattern of 1 ram in length and 1 ram in width.
．． It was dried at 20'C for 20 minutes and fired using a belt firing furnace at a peak temperature of 850'C for a peak time of 10 minutes. The length thus obtained was 1 mm.

The sheet resistance value, CV value, and permanent resistance change rate of a resistor having a width of 15 μm and a thickness of 15 μm were measured. The voltage intensity applied when measuring the permanent resistance change rate is J Engineering SO5202.
It was calculated using the following formula.

Applied voltage (V) - (Overload Previous article "1 x Rated power x Sheet resistance 1"/'□ This is 10 times the overload condition, and the rated power is calculated as 1 x 4w, rounding off to the nearest 100. The applied voltage was determined by using the sheet resistance value of 1M97.
In the case where the voltage was higher than that, the applied voltage was kept constant at 1600 V.

The applied voltage determined in this way was applied for 5 seconds, then the sheet resistance value was determined, and the permanent resistance change rate was determined from the difference between the sheet resistance values before and after the application.

Table 1 shows the composition of the composition for thick film resistors, the applied voltage, and the measurement results obtained.

Table 1 shows that if the composition for thick film resistors of the present invention is used, a high resistance value, a small CV value, and a permanent resistance change rate of 0.2 can be obtained.
It can be seen that a resistor with excellent characteristics of less than % can be obtained.

Table 1 Comparative Example A resistor was prepared in the same manner as in the example except that the proportion of Pb5nO powder with an average particle size of 3.2 μm was changed to 0°0.1 and 2.4% by weight, and its aV value and permanent resistance change The ratio was measured and the results are shown in Table 2.

From Table 2, it can be seen that only those with a large Cv value and a large permanent resistance change rate were obtained.

Table 2 [Effects of the Invention] By using the composition for a thick film resistor of the present invention, it becomes possible to manufacture a thick film resistor having a small CV value and a small rate of change in permanent resistance due to a short-time overload test.

Applicant: Sumitomo Metal Mining Co., Ltd. '4 (evening)

Claims (1)

[Claims] (1) Expression Pb_2Ru_2O_x where the range of x is 6
~7 and the particle size is less than 1000 Å and lead ruthenate and 1
Lead silicate glass powder containing 0% by weight or more of silicon oxide and 10% by weight or more of lead oxide and having an average particle size of 10 μm or less, or represented by the formula Pb_2Ru_2O_x, where x is in the range of 6 to 7 and the particle size is 1000 Å or less lead ruthenate powder, and 1
The composition consists of lead silicate glass powder with an average particle size of 10 μm or less containing 0% by weight or more of silicon oxide and 10% by weight or more of lead oxide, lead stannate powder, and an organic vehicle, and an inorganic component in the composition. A composition for a thick film resistor, characterized in that the content of lead stannate therein is 0.2 to 2% by weight.